Figure 3.

Breast cancer cells migrate through microporous membranes to human bone tissue fragments. (A) Nontraditional “reverse” migration assay design showing MDA-MB-231-fLuc-EGFP cells seeded onto the lower surface of an insert with an 8-μm porous membrane, through which they migrate to colonize a bone tissue fragment or a control glass bead. (B) Following colonization, fragments and glass beads are transferred to fresh culture wells at 24 h. (C) BLI detects breast cell colonization of bone fragment but not glass bead at 24 h. (D) Histogram showing the number of tissue fragments and glass beads with versus without bioluminescence signal. Experiments were performed in triplicate (n = 3 fragments and 3 beads) for each of 14 THR specimens. Signal was observed in a significantly greater number of bone tissue fragments (15/42) versus glass beads (3/42) (^*P = .003).